diff --git a/src/cc/mallet/types/InstanceList.java b/src/cc/mallet/types/InstanceList.java
index d4aa0e010..9de5ef9f2 100644
--- a/src/cc/mallet/types/InstanceList.java
+++ b/src/cc/mallet/types/InstanceList.java
@@ -831,6 +831,22 @@ private void readObject (ObjectInputStream in) throws IOException, ClassNotFound
 		int version = in.readInt ();
 		instWeights = (HashMap<Instance,Double>) in.readObject();
 		pipe = (Pipe) in.readObject();
+		if (dataAlphabet == null) {
+			if (size()>0) { 
+				Instance instance = get(0); 
+				dataAlphabet = instance.getDataAlphabet (); 
+			}  else if (pipe.getDataAlphabet()!=null) {
+				dataAlphabet = pipe.getDataAlphabet ();
+			}
+		}
+		if (targetAlphabet == null) {
+			if (size()>0) { 
+				Instance instance = get(0); 
+				targetAlphabet = instance.getTargetAlphabet (); 
+			}  else if (pipe.getTargetAlphabet()!=null) {
+				targetAlphabet = pipe.getTargetAlphabet ();
+			}
+		}
 	}
 
 	// added - culotta@cs.umass.edu